Suppression of insect pest populations and damage to plants by vermicomposts.

The effects of commercial vermicomposts, produced from food waste, on infestations and damage by aphids, mealy bugs and cabbage white caterpillars were studied in the greenhouse. Vermicomposts were used at substitution rates into a soil-less plant growth medium, MetroMix 360 (MM360), at rates of 100% MM360 and 0% vermicompost, 80% MM360 and 20% vermicompost, and 60% MM360 and 40% vermicompost to grow peppers (Capsicum annuum L.), tomatoes (Lycopersicon esculentum Mill.) and cabbages (Brassica oleracea L.), in pots. Groups of 10 pots containing young plants were distributed randomly in nylon mesh cages (40 cm x 40 cm x 40 cm). Groups of 10 pepper seedlings in a single cage were infested with either 100 aphids (Myzus persicae Sulz.) or 50 mealy bugs (Pseudococcus spp.) per cage. Similar groups of tomato seedlings were infested with 50 mealy bugs per cage. Groups of four cabbage seedlings in pots in cages were infested with 16 cabbage white caterpillars (Pieris brassicae L.). Populations of aphids and mealy bugs were counted after 20 days and the shoot dry weights of peppers, tomatoes and cabbages were measured at harvest. Numbers of cabbage white caterpillars and loss in shoot weights were measured after 15 days. The substitution rates of 20% and 40% vermicomposts suppressed populations of both aphids and mealy bugs on peppers, and mealy bugs on tomatoes, significantly. Substitutions with vermicomposts into MM360 decreased losses of dry weights of peppers, in response to both aphid and mealy bug infestations, decreased losses in shoot dry weights of tomatoes after mealy bug infestations significantly. There were significantly decreased losses in leaf areas of cabbage seedlings in response to the cabbage white caterpillar infestations.

Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers.

Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter's Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10-80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained.

Proximate analysis, in vitro organic matter digestibility, and energy content of common guava (Psidium guajava L.) and yellow, strawberry guava (Psidium cattleianum Var. lucidum) tree parts and fruits as potential forage.

The nutrient composition of common guava, Psidium guajava L., and strawberry guava (waiwi), Psidium cattleianum var. lucidum, tree parts and fruits was determined during three seasons for six locations in Hawaii to assess guava as a potential feed for cattle. All guava plant parts were higher (p < 0.001) in crude protein than waiwi, but there were no differences in the fiber and energy densities for bark, shoots, and branches. Guava leaves were higher in fiber and had lower energy densities (p < 0.05) than waiwi. Ripe and breaker stage fruits were lower (p < 0.05) in fiber, similar in protein (CP), and higher (p < 0.05) in energy density than immature fruits. Guava fruits were higher in CP (p < 0.05) and organic matter (p < 0.001) and lower in ash (p < 0.001) than waiwi fruits. The primary nutritional concern with guava is low in vitro organic matter digestibility as compared to tropical forage grasses; therefore, it is not recommended as a feedstock for livestock.