MECHANICAL PROTECTION OF 'SMOOTH CAYENNE' PINEAPPLE (ANANAS COMOSUS L. MERR.) INFLORESCENCE AND FRUIT, AND ITS EFFECT ON 'FRUIT ROT' IN CHANCHAMAYO - PERU

A field test was carried out in the Peruvian Central Forest (Chanchamayo) to determine what effect mechanical protection on inflorescence and fruits has on fruit rot incidence in Smooth Cayenne Pineapple. Inflorescences were protected at 75 (T1), 105(T2), 135(T3), and 165 (T4) days after Flower Induction Treatment (TIF), and compared to an unprotected null variable sample (T5) harvested 185 days after the TIF. The field test was carried out in a commercial plot of approximately 0.5 hectares. For each treatment, 20 plants were taken at random and protected with a commercial mesh bag (PVC Number 32/14x14). A random sample design was used, based on 5 treatments and 20 repetitions. Channeled Rot (Mancha Con Galerías-MCG) had the highest incidence, followed by Leathery Pocket or Interfruitlet Corking (Mancha Negra Seca-MNS), and finally by Fruitlet Core Rot or Taches Noires (Mancha Negra-MN). The incidence of the MCG in treatments T5 (95%), and T4 (74%) was statistically similar, followed by T3 (19%), which was significantly smaller. When inflorescence was protected at 75 (T1), and 105 (T2) days after TIF, complete control of the infection was achieved. Fruit fly larvae (Melanoloma canopilosum) were not found in the fruits of treatments T1 and T2, but were found in T3, T4 and T5. A trend towards the increase in larvae/fruit numbers was observed when the number of days between the TIF and the protection of inflorescence buds was longer, but there were no significant statistical differences between treatments. The correlation between the number of fruit fly larvae (Melanoloma canopilosum) and the MCG was significant (r=0.6656**), as well as the correlation with the MN (r=9.3932*), but was not significant with the MNS (r=0.1548). The protection of inflorescence and/or of the fruit did not have an effect on fruit characteristics evaluated during this experiment.