RELEASE OF 'CAMUY': A WHITE -FLESHED SWEET POTATO

Kaki and 28-Bushy pigeon peas were grown in the southern plains of Puerto Rico, in four spatial arrangements with six intervals of weed competition during two growing seasons to determine the influence of weed competition on crop growth, development and yield. In both growing seasons, Cleome gynandra, Amaranthus dubius, Echinochloa colona, Leptochloa filiformis, and Digitaria sanguinalis were the dominant weeds. C. gynandra and E. colona dominated the early weed flora until approximately 40 days after pigeon pea emergence. Later, weed flora was dominated by L. filiformis, D. sanguinalis, and A. dubius. The presence of weeds during early growth stages reduced initial crop growth and delayed differentiation including flowering of the two pigeon pea cultivars. Elimination of weeds at or before 21 to 28 days after pigeon pea emergence and thereafter, generally resulted in the recovery of pigeon pea plants and prevented measurable losses in final yield. The critical period for removing weeds in pigeon peas appeared to vary between the pigeon pea cultivars and between the two growing seasons. In the May 6 planting, pigeon pea yields were reduced after 28 and 21 days of early competition for Kaki and 28-Bushy, respectively. In the July 1 planting, however, losses occurred at 21 and 14 days of weed competition for the two respective cultivars. No differences were found in weed numbers or yield between the two cultivars or among spatial arrangements in either planting season. However, weed number and yield were greater during the first planting season compared with those of the second. Planting pigeon peas under short photoperiods accelerated vegetative growth, shortened the total cropping cycle, and resulted in reduced yield and total growth for both cultivars. Losses from early weed competition occurred earlier under the short-day planting than those under the long-day planting.

Control of black Sigatoka disease in plantains is imperative for adequate yield. Black Sigatoka is caused by the fungus Pseudocercospora fijiensis (Morelet) Deighton, formerly known as Mycosphaerella fijiensis Morelet. The disease does not immediately kill the plants, but by reducing the effective leaf area it interferes with photosynthesis (Churchill, 2011). If not controlled, the disease has the potential to devastate plantain fields. In Puerto Rico, the main plantain cultivar is 'Maricongo', a false-horn clone which is susceptible to black Sigatoka. Locally, a combination of synthetic pesticides and the sanitary removal of leaves, or parts of them, are used to control the disease. As suggested by Goenaga and Irizarry (2006), the use of French-type plantain clones may result in increased yield via increased production of fruits and by the tolerance of these clones to black Sigatoka. Resistance to this disease appears to be associated with French-type parents as the source of resistance in Musaceae breeding programs (Goenaga and Irizarry, 2006). A French-type tetraploid (AAAB) plantain cultivar, 'FHIA-21' was developed by the "Fundación Hondureña de Investigación Agrícola" (FHIA) at La Lima, Honduras. Major attributes of this cultivar are its high tolerance to black Sigatoka and higher yields than false-horn clones (Rowe, 1997; Hauser, 2010; Calvo, 2010); details for the plant characteristics of 'FHIA-21' were summarized in its patent (Rowe, 1997). However, 'FHIA-21' is susceptible to the Banana Streak Virus (Martínez et al., 2015), a virus that limits plant development and consequently reduces its yield potential

RELEASE OF 'PUJOLS': A TROPICAL-TYPE SWEET POTATO

In 1982, the bipyridilium herbicides diquat [6,7-dihydrodipyrido (1,2- :2;i-c) pyrazinediium ion] at 0.56, 1.12 and 2.24 kg ai/ha, and paraquat [1, 1-dimethyl-4,4' -bipyridinium ion] at 2.24 kg ai/ha were evaluated for postemergence control of weeds in pumpkin cv. Borinquen (Cucurbita moschata (Duchesne) Poir). The experiment was established in Fraternidad clay soil, a Vertisol at the Lajas Substation, Agricultural Experiment Station. No statistical differences (P=0.05) in yield were detected among the hand-weeded plots (25,580 kg/ha), diquat treated plots (23,296 kg/ha), and paraquat treated plots (27,341 kg/ha). Significant differences in plot yield were observed among paraquat 2.24 kg rate treatment, diquat at the lower rates, and the non-weeded plots. Yields were 0.56 kg diquat (17,172 kg/ha), 1.12 kg diquat (19,551 kg), and non weeded check (10,243 kg/ha). All rates of herbicides provided 100% control of Ipomoea tillacea L.; the higher rates also controlled over 85% Euphorbia heterophylla. Control of grass weeds was inefficient (10% or less) with diquat sprays 1 month after the second herbicide application. Nevertheless, diquat seems to be a promising candidate herbicide for postemergence weed control in pumpkin since it efficiently controlled broad leaf weeds with less toxic effect on applicators than paraquat.