Growth, Nutrient Content and SPAD Value of Corn in Monoculture and in Intercropping

The objective of this study was to evaluate the growth, the nutrition, and the intensity of the green color in corn plants in monoculture and in intercropping with Mucuna aterrima, Crotalaria juncea, and Canavalia ensiformis, cultivated with different handlings. In general, corn plants in monoculture demonstrated greater growth and greater SPAD value in the first evaluation, despite presenting lower tenor of phosphorus in the leaves when related to the corn in intercropping. The weed helps in the growth of the corn plant and increases the SPAD value during flowering. The monoculture NPK (Nitrogen, Phosphorus and Potassium) fertilization promoted higher values in corn plant growth, as well as a greater SPAD value, at 30 d.a.e., of the plants. The NPK-fertilized corn plants showed a greater tenor of sulphur and a lower tenor of molybdenum. The corn in intercropping with M. aterrima resulted in smaller plants at 70 d.a.e. It also presented a greater tenor of molybdenum and lower tenor of nickel when compared to intercroppings with C. juncea and with C. ensiformis. The corn plants in a intercropping with Crotalaria juncea presented higher growth at 30 and 70 d.a.e. and greater tenors of molybdenum when compared to the plants in intercropping with C. ensiformis.

Emergence of Conilon Coffee Seedlings Originating from Seeds Treated with a Sodium Hypochlorite Solution

The coffee seeds are problematic for the physiologycal quality, featuring low speed of seedling emergence. In this sense, this work was developed with the objective of evaluating the effect of sodium hypochlorite in the removal of the parchment and in the emergence and seedlings development of conilon coffee in nursery conditions. Coffee seeds of the variety Victoria were used, which were harvested in the cherry stage and pulped by hand. Seeds were dried in an oven with forced ventilation until reaching moisture contents of 35%, 30% and 25% wet basis. Then, the seeds with parchment were soaked in a sodium hypochlorite solution with concentrations of 4%, 5%, 6% and 7% active chlorine for 3 and 6 hours. For each moisture content, two additional treatments were added consisting of seeds with parchment and seeds in which the structure was removed manually. The characteristics evaluated were: emergence speed index, total emergence, dry mass of the shoots and root system. Utilization of sodium hypochlorite promoted an acceleration in seedling emergence speed similar to the method for manual removal of the parchment when using concentrations of 4%, 5%, 6% and 7% for 3 hours, at all moisture contents.