NITROGEN AND POTASSIUM FERTILITY AFFECTS JALAPENO PEPPER PLANT-GROWTH, POD YIELD, AND PUNGENCY

The influence of N and K rates in Hoagland's nutrient solution on Jala peno pepper (Capsicum annuum L.) plant growth and pod production was d etermined on greenhouse-grown plants in sand culture. Varying the rate s of N (1 to 30 mM) and K (1 to 12 mM) in Hoagland's solution identifi ed optimum concentrations for Jalapeno plant growth and pod production . Two experiments mere conducted to determine Jalapeno pepper sensitiv ity to differential fertilization. In the experiment seeded in April, nutrient treatments began at transplanting, and in the one seeded in M ay, treatments began after all plants had flower buds and half had flo wered. Biomass and pod production per plant responded curvilinearly to N rate in both experiments. Optimum N rate for pod yield was 15 mM. N itrogen rate affected pungency of pods only in the first experiment, w ith 1 mM N reducing capsaicin levels in fruit compared to other N rate s. Biomass, fruit count, and fruit weight per plant increased linearly with increasing K rate in the first experiment and curvilinearly with K rate in the second experiment. The optimum K rate for pod yield was 6 mM. Potassium rates did not affect pod pungency. Jalapeno peppers g rown in sand culture required 15 mM N and at least 3 mM K for optimum pod production.