Morpho-anatomical and chemical adaptations of black pepper (Piper nigrum L. cv. Trioicum) to varying light intensities and nitrogen levels
1989
Reglos, R.A.
The effects of different levels of shade and nitrogen fertilizer on the growth of black pepper (Piper nigrum L. cv. trioicum) were determined. Rooted leader stem cuttings were grown in pots and exposed to 0%, 25%, 50% and 74% shade. Fertilizer treatments included the application of ammonium sulfate at 0 (F1), 35.71 g/plant (F2), 47.62 g/plant (F3) and 59.53 g/plant (F4). F3 is the recommended rate for N based on soil analysis while the other two rates are 25% above and below the recommended rate. Significant differences were observed on the effect of light intensity on each parameter measured. High light intensity (0% shade) favored the production of more leaves, higher number of nodes and branches though the average length of the vine and area per leaf were reduced. Early flowering and consequently the production of large number of spikes was associated with those level of shade. However, spike abscission was also highest at full sunlight. Plants exposed 25% shade gave the number of spikes produced, longer spikes, highest fruit set per spike, bigger pepper corns, highest piperine content and lowest spike abscission. On the other hand, extreme shade (75%) induced excessive vegetative growth of the plants, hence the flowering process was delayed. Increasing rate of N fertilizer applied per plant significantly increased both the piperine and leaf chlorophyll contents of black pepper. The overall thickness of leaf blades, palisade and spongy mesophyll cells increased with increasing of light intensity and N fertilizer. High light intensity significantly decreased the leaf N, P, and K contents of black pepper and consequently its uptake. Similarly, an increase in N fertilizers rate had increased the leaf N content but lowered its P and K contents.
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