the invention is further illustrated by the following non - limiting examples . it is to be appreciated that , although each of the exemplary experiments used potassium phosphite , that other salts of phosphorous acid , including without limitation , ammonium , sodium , and / or calcium salts , as well as phosphorous acid itself may also have been used . for examples 1 and 2 below , assessment of citrus fruit peel color was made using the following color grading charts ( fig1 for navels ; fig2 for lemons ) in addition to the dictionary of color by maerz and paul , first edition ( 1930 ). all experiments were conducted in solutions at approximately ph 6 , although ph ranges from between about 3 and about 9 are acceptable . table 1 below sets forth approximate cross - references to the dictionary of color for the eight colors of fig1 : five different treatments ( a - e below ) were made . there were four replications for each of the five treatments , with each replicate comprising six fruit pieces . thus , each treatment was applied to 24 fruit pieces . the fruit treated in this example were green lemons ( initial color between stage 5 and 6 ( approx 5 . 5 ) at the color break stage . possible immersion temperatures can be between approximately 45 ° f . ( 7 ° c .) and 150 ° f . ( 66 ° c . ), with an ideal temperature of 50 ° f . ( 10 ° c .) which was used in the trials below . a . the fruit was immersed in untreated water . b . the fruit was immersed in a solution of gibberellic acid ( 100 ppm ) in water for 2 minutes . c . the fruit was immersed in a water solution containing 2 % ( w / w ) potassium phosphite for 2 minutes . d . the fruit was immersed for 2 minutes in a water solution containing a mixture of 2 % ( w / w ) potassium phosphite and gibberellic acid ( 100 ppm ) e . the fruit was immersed for 2 minutes in a mixture of gibberellic acid ( 100 ppm ) and a 3 % ( w / w ) potassium phosphite solution . after the treatments were applied and left to dry for 10 minutes , all treatments were recorded for peel color using fig2 above and the dictionary of color , and rated for color development and photographed . the fruit was placed in humid incubators at 15 ° c . and monitored weekly for color development . five different treatments ( a - e below ) were made . there were four replications for each of the five treatments , with each replicate comprising six fruit pieces . thus , each treatment was applied to 24 fruit pieces . the fruit treated in this example were oranges at the color break stage , the fruit being predominantly green with some development of orange color ( initial color 5 . 5 ). possible immersion temperatures can be between approximately 45 ° f . ( 7 ° c .) and 150 ° f . ( 66 ° c . ), with an ideal temperature of 50 ° f . ( 10 ° c .) which was used in the trials below . a . the fruit was immersed in untreated water . b . the fruit was immersed in a solution of gibberellic acid ( 100 ppm ) in water for 2 minutes . c . the fruit was immersed in a water solution containing 2 % ( w / w ) potassium phosphite for 2 minutes . d . the fruit was immersed for 2 minutes in a water solution containing a mixture of 2 % ( w / w ) potassium phosphite and gibberellic acid ( 100 ppm ) e . the fruit was immersed for 2 minutes in a mixture of gibberellic acid ( 100 ppm ) and a 3 % ( w / w ) potassium phosphite solution . after the treatments were applied and left to dry for 10 minutes , all treatments were recorded for peel color using fig1 above and the dictionary of color , and rated for color development and photographed . the fruit was placed in humid incubators at 15 ° c . and monitored weekly for color development . table 3 below sets forth results of fruit dipping examples 1 and 2 , with color references to the charts of fig1 and 2 . treatments followed by the same letter in each row are not significantly different at p = 0 . 05 according to the student neuman - keuls test at a probability level of p = 0 . 05 . fig3 illustrates representative fruit from example 2 after 30 days in . from top to bottom , the 5 rows of fruit represent the 5 treatments : a ( control ), b ( ga 100 ppm ), c ( phosphite ), d ( phosphite 2 %+ ga 100 ppm ) and e ( phosphite 3 %+ ga 100 ppm ). table 4 below sets forth approximate colors from the dictionary of color corresponding to the five rows of fruit of fig3 : five different treatments ( t1 - t5 below ) were made . there were four replications for each of the five treatments , with each replicate comprising one navel orange tree ( variety cara cara ) in situ . thus , each treatment was applied to 4 different trees . treatments were all made using a motorized high volume agricultural sprayer and an application volume equivalent to 5000 l / ha ( liters / hectare ), or approximately 530 gallons / acre . this is approximately equivalent to 12 . 5 l ( 3 . 3 gal )/ tree . the trees were sprayed during early color break ( late october / early november ) with a wetting agent added at 0 . 01 % ( v / v ). t1 . untreated trees = control . t2 . water solution containing gibberellic acid at 16 ppm . t3 . water solution containing potassium phosphite ( expressed as equivalent amount of phosphorous acid ) sprayed at 600 ppm . t4 . a tank water mixture of potassium phosphite ( expressed as equivalent amount of phosphorous acid ) sprayed at 300 ppm plus gibberellic acid at 16 ppm t5 . a tank water mixture of potassium phosphite sprayed at 600 ppm plus gibberellic acid at 16 ppm the spray tank ph for all the treatments t2 - t5 were adjusted with citric acid to a ph of between about 5 and about 6 ( in accordance with the manufacturers instructions for gibberellic acid usage ), and a small amount of a non ionic wetter added to the tank ( 0 . 01 % v / v ). at the time of application , field temperatures varied between about 0 - 10 ° c . ( night ) [ 32 - 50 ° f .] and about 10 - 25 ° c . ( day ) [ 50 - 77 ° f .]. the fruit on the trees were assessed for color development approximately 30 days later , during december . table 5 below sets forth results of field trial example 4 on the fruit of the subject trees with color references to the chart of fig1 . treatments followed by the same letter in each row are not significantly different at p = 0 . 05 according to the student neuman - keuls test at a probability level of p = 0 . 05 . the above temperature ranges reflect the ambient high and low temperatures in central california during the late fall season , prior to citrus harvest . it is to be appreciated that for application to crops harvested in the spring or summer , the ambient temperature may range between about 20 ° c . and 30 ° c . ( 68 - 86 ° f .) in mild conditions , and as low as about 10 ° c . ( 50 ° f .) to as high as about 37 ° c . ( 99 ° f .). it is not recommended that the materials of the present invention be applied at temperatures much higher than about 30 ° c . ( 86 ° f . ), with the preferred temperature range being between about 10 ° c . and about 30 ° c . for example 4 below , assessment of the tomato peel color was made using the usda color grading chart ( fig5 ) in addition to the dictionary of color . the color grading chart ( fig5 ) is a reproduction of the “ tomato color standards usda visual aid tm - l - 1 ” which consists of a chart containing twelve color photographs illustrating certain color classification requirements . the official usda chart is incorporated herein by this reference . table 6 below sets forth approximate cross - references to the dictionary of color for the 12 colors of the usda chart : in example 4 , five different treatments ( a - e below ) were made . there were four replications for each of the five treatments , with each replicate comprising six fruit pieces . thus , each treatment was applied to 24 fruit pieces . the fruit treated in this example were firm green tomatoes according to the chart above was 3 . 5 ( initial color 11 - c - 22 ) at the onset of color break . immersion temperatures were approximately 75 ° f . ( 24 ° c .). a . the fruit was immersed in untreated water . b . the fruit was immersed in a solution of gibberellic acid ( 100 ppm ) in water for 2 minutes . c . the fruit was immersed in a water solution containing 2 % ( w / w ) potassium phosphite for 2 minutes . d . the fruit was immersed for 2 minutes in a water solution containing a mixture of 2 % ( w / w ) potassium phosphite and gibberellic acid ( 100 ppm ) e . the fruit was immersed for 2 minutes in a mixture of gibberellic acid ( 100 ppm ) and a 3 % ( w / w ) potassium phosphite solution . after the treatments were applied and left to dry for 10 minutes , all treatments were recorded for peel color using the dictionary of color and also the usda tomato color standards chart ( fig5 herein ), and rated for color development and photographed . the fruit was placed in humid incubators at 30 ° c . ( 86 ° f .) and monitored weekly for color development . table 7 below sets forth results of example 5 on the subject tomatoes with color references to the chart of fig5 . treatments followed by the same letter in each row are not significantly different at p = 0 . 05 according to the student neuman - keuls test at a probability level of p = 0 . 05 . fig6 illustrates representative fruit from example 4 . table 8 sets forth approximate colors from the dictionary of color corresponding to the three rows of fruit of fig6 : five different treatments ( a - e below ) were made . there were four replications for each of the five treatments , with each replicate comprising ten grape leaves . thus , each treatment was applied to 40 leaves . the leaves treated in this example were green ( initial color 30 - l - 12 ). immersion temperatures were between approximately 75 ° f . ( 24 ° c .). a . the leaves were immersed in untreated water . b . the leaves were immersed in a solution of gibberellic acid ( 100 ppm ) in water for 2 minutes . c . the leaves were immersed in a water solution containing 2 % ( w / w ) potassium phosphite for 2 minutes . d . the leaves were immersed for 2 minutes in a water solution containing a mixture of 2 % ( w / w ) potassium phosphite and gibberellic acid ( 100 ppm ) e . the leaves were immersed for 2 minutes in a mixture of gibberellic acid ( 100 ppm ) and a 3 % ( w / w ) potassium phosphite solution . after the treatments were applied and left to dry for 10 minutes , all treatments were recorded for color using the dictionary of color , and rated for color development . leaves were placed in humid incubators at approximately 25 ° c . ( 77 ° f .) and monitored daily for color development . the above experiments show that phosphorous acid / salts ( phosphites ) alone and gibberellic acid / salts alone each inhibit the maturation and ripening process of plant products such as fruit , vegetables and non food crops . however , the combination of phosphorous acid and / or its salts with gibberellic acid and / or its salts provides highly effective inhibition of maturation and delay in color development . the unique combinations of phosphorous acid / salts with gibberellic acid / salts in embodiments of the present invention increase the effect of the gibberellic acid / salts on delaying maturation and senescence of plant tissues , thereby prolonging the shelf life of fruit , vegetables and / or non food crops in ways not previously realized . preferred ph ranges are between approximately 4 . 5 and 6 . the maturation delaying effect is more pronounced at higher temperatures . it is to be appreciated that the term “ crop ” referred to herein and in the appended claims is to be interpreted broadly to include any harvestable portion of a plant that may be used for commercial purposes , and includes without limitation , fruit , vegetables , leaves , any part of a flower ( including without limitation such things as saffron and lavender ), stems , roots , shoots , seeds , pods , nuts , bulbs , etc ., or any part or portion thereof . it is to be understood that variations , permutations , combinations and modifications of the present invention may be made without departing from the scope thereof . one or more features of an exemplary embodiment as described above may be practiced in conjunction with other exemplary embodiments as described above . it is also to be understood that the present invention is not to be limited by the specific embodiments or experiments disclosed herein , but only in accordance with the appended claims when read in light of the foregoing specification .
methods for delaying the maturity , coloration and / or senescence of fruits , vegetables , ornamentals , or non - food crops by applying phosphorous acid and / or its salts to the plants ; or by applying mixtures of gibberellic acid and / or its salts and phosphorous acid and / or its salts to the plants . applications may be made pre - or post - harvest at various temperatures and ph ranges . the unique combinations of phosphorous acid / salts with gibberellic acid / salts in embodiments of the present invention have been found to increase the effect of the gibberellic acid / salts on delaying maturation , coloration and senescence of plant tissues , thereby prolonging the shelf life of fruit , vegetables and / or non food crops in ways not previously realized .