Effect of Production Inputs On Jalapeño Pungency

Processing and fresh market jalapeño growers are interested in fruit capsaicin content.  They would like to grow fruit of high yielding capabilities, good quality, and consistent pungency.  In this field study, we want to assess the impact of various production inputs on jalapeño fruit yield and capsaicin concentration. The goal of this field trial is to assess the impact of several inputs on yield and capsaicin concentration of jalapeño fruit. The study compares the effect of normal production inputs to stressful input strategies and their respective influence on capsaicin accumulation in jalapeño fruit.  We contrasted normal production practices to stressful 50% nitrogen (N) fluctuation from control, low water, and sea salt addition.  Low water treatment was achieved by irrigation cut off two weeks prior to harvest. Plot consisted of three single-row beds, 160 ft long.  Only the middle bed was used for data.  At harvest, 10-pound subsample was collected from each row.  Each subsample was evaluated for fruit count, fruit size, and dimensions.  A second sample of 100-fruit per row was analyzed for capsaicin concentration. Two harvests were carried out on September 2 and October 21, 2010. As expected, water input affected yield.  All treatments receiving adequate water level produced higher yields than those subjected to water cut-off.  Among low water treatments, those receiving higher N slightly increased yield in contrast to those receiving less water.  However, reducing N resulted in the lowest yield.   Fruit size decreased with decreasing water input as well. Reducing N input resulted in the highest Scoville heat units (SHU) in jalapeño fruit.  Adding sea salt, increasing N and reducing water all reduced SHU’s below control level. In the amount of capsaicin produced by each treatment, it is apparent that reducing N still ranked high.  Reducing water, adding extra N or adding salt had similar depressive effect on capsaicin levels.  Furthermore, combining water cut-off with higher N application resulted in the lowest capsaicin production by any treatment in this trial.  Differently stated, higher N application resulted in similar capsaicin production levels as lower water input, while combining both further decreased it.