HighlightsGrafting can transfer floral stimulus between different cassava genotypes.Grafting in early stage increase plant survival and favor the flowering induction.High fruit set were found in low flowering genotypes when grafted onto high flowering ones.The use of grafting in cassava affected the aboveground yield and harvest index.

The slow rate of multiplication is one of the main constraints on the production of cassava (Manihot esculenta Crantz). This work aimed to evaluate the use of leaf buds for rapid propagation of cassava varieties. Leaf buds were excised from three cassava varieties (BRS Kiriris, 98150-06 and 9624-09) for plantlet generation. The experiment was completely randomized with a 5 (age of mother plant) × 3 (position of the leaf buds on the stems) × 2 (agrochemical treatments) factorial design. Data were collected on leaf sprouting percentage (Spro.Per), plantlet height (Plant.Hei) and total dry mass of plantlets (Dry.Mass.Plant). There was a difference between the three traits for most of the varieties, demonstrating significant effects on the agronomic attributes evaluated. Better agronomic performance (higher sprouting percentage, plantlet height and total dry mass) in plantlets was observed in leaf buds of: i) maturing plants up to six months old; ii) more herbaceous (upper) parts; and iii) plants treated with agrochemicals (fungicides and insecticides). Considering four-month-old plants, three annual cycles, and an 81 % average sprouting, it would be possible to reach an annual multiplication rate of 1:72, which is much higher than that achieved by traditional methods using mature stem cuttings from 12-month-old plants (around 1:5). These results are important because they demonstrate the possibility of using cassava leaf buds to produce high-quality plantlets rapidly for greater multiplication and diffusion of new varieties and cultivation on a larger scale. Plantlet preparation and data collectionThe aboveground parts of the plants were collected early in the morning to ensure greater turgidity of the material (Hartmann et al., 2011) and then sent to the greenhouse to set up the experiments. Initially, the leaf blade was cut (1/3 of the original size) using clean scissors, and the stems were placed in water containers to avoid leaf wilting. The leaf buds from different stem locations were identified (i.e., buds from the upper region -herbaceous part; buds from the middle region -intermediate part; and buds from the lower region -lignified part; Figure 1). Next, a "V" cut on the stems was made using a sterilized scalpel. The leaf bud cuttings were planted in 290 cm 3 plastic tubes containing vermiculite and washed sand (1:1 ratio) in the upper part of the tube (1/4 of the total volume). The substrate of the lower part of the plastic tube (3/4 of the total volume) was composed of vermiculite, soil and coconut fiber (1:2:1 ratio), 15 mg of single superphosphate and 15 mg of ammonium sulfate.The cutting was performed at five different times: the first cutting was at 4 months after planting (4 MAP), the second at 6 MAP, the third at 8 MAP, the fourth at 10 MAP and the fifth at 12 MAP. Moreover, since the cutting process can cause injuries to cassava cuttings with subsequent direct exposure of this vegetative structure to the substrate, the effects of applying a fungicide and an insecticide to prevent damage to cuttings ...

New techniques of rapid multiplication of cassava (Manihot esculenta Crantz) have been developed, requiring technical support for large-scale use. This work main to evaluate the agronomic performance of plantlets obtained by leaf buds technique against stem cuttings in the field conditions. The work was conducted using the randomized block design in a factorial scheme with 3 varieties (BRS Kiriris, 98150-06, 9624-09) × 4 origins of the plantlets (conventional - stem cuttings of 20 cm length, leaf buds of the upper, middle and inferior stem part) × 2 agrochemicals (control and treated). There was a remarkable decrease in some agronomic traits that ranged from 23% (number of branches) to 62% (shoot weight) when using leaf buds plantlets. The treatment of plantlets with agrochemicals promoted significant increases in all traits, ranging from 26% (number of roots per plant) to 46% (shoot weight). The plantlets originating from leaf buds of the upper and middle parts were able to generate stem-like plants similar to stem-derived ones. Despite its lower agronomic performance under field conditions, multiplication by leaf buds may generate five times the number of propagules in comparison with the conventional multiplication, and therefore it could be a viable alternative for rapid cassava multiplication.