Five trials were developed under greenhouse conditions aiming to evaluate the influence of sowing depth and soil cover condition on seedling emergence of five Convolvulaceae family species (Ipomoea hederifolia, I. nil, I. quamoclit, I. triloba and Merremia cissoides). A factorial scheme was used for four sowing depths (0, 20, 40 and 80 mm) and two soil conditions (exposed or covered with sugarcane straw in an amount proportional to 10 t ha-1);arranged in a randomized block design and four replicates. Emerged seedlings were counted daily and, at the end of the trials, emergence index speed was calculated. Regarding soil-sowing depth, higher emergence was observed for seeds distributed on the soil surface, both in the presence and absence of straw. Considering emergence of I. hederifolia and I. nil, no soil cover nor even depth x cover interaction effects were observed. For I. quamoclit, isolated soil cover effects and seed distribution depth were observed, indicating better adaptability of the species to emerge in soil without the presence of straw on the surface. Also for the species I. triloba and M. cissoides, emergence was lower in the plots with straw on the soil surface, compared to those without straw. In addition, straw distributed on the soil surface reduced emergence speed and seedling establishment.
Ipomoea; Merremia; morningglory; biology; Saccharum
