Fig 1.
General schematic representation of treatments.
(A) Pruning and defoliation. (B) New flush shoots. (C) Selection of flush shoot at the beginning of stage V2. (D) Pruning and selection period of the remaining groups for final standardisation and insect caging.
Fig 2.
Adjusted curve describing flush shoot length (continuous line; sigmoidal logistic curve selected based on the AIC [59]), elongation rate per day (dashed line) and approximate duration and length of each stage during ontogeny (vertical lines are standard error of the mean of the original data, n = 4 plants) (See S1 Apendix).
Fig 3.
Ontogeny of flush shoot of ‘Valencia’ sweet orange plants.
Stage V1: from bud swelling (A) to bud emergence with less than 2 mm flush stem (white square bracket) (B). Stage V2: from initial stem elongation with separation between basal petioles (C) but all margins of the leaves remaining closed (D). Stage V3: from initial leaf blade expansion and separation of the flush axis (E) with margins of lower leaves opening (F) until new leaves emission stops. Stage V4: from unfolding of all leaf (G) and final leaf number defined (H) to shoot tip chlorosis. Stage V5: leaves fully expanded, green-light yellow coloured, gradual hardening from top to base (I), and shoot tip chlorosis and/or abscission (J). Stage V6: vegetative flush completely matured with leaves fully hardened and green-dark (K) and with dormant buds (L). Comparison between fully expanded, partially hardened and green-light-yellow leaf from a V5 shoot and one fully expanded, hardened and final green-dark leaf from a V6 flush (M). For relative sizes and duration of each stage see Fig 2.
Fig 4.
Oviposition by Diaphorina citri.
Means (±SEM) of the number of eggs laid by Diaphorina citri on different flush stages of ‘Valencia’ sweet orange plants grown under controlled environmental room (black bars; 26°C ± 2, 70% RH ± 5, 12h photoperiod) and screen-house (grey bars; 25°C ±8, 53% ±21 HR and 12h photoperiod) conditions. No eggs were laid in stage V6 in both ambient. Bars with different letters differ by Tukey-HSD test, P < 0.05 (lowercase for CER and lowercase with quote for SH; no comparisons were made between ambient).
Fig 5.
Mean (±SEM) values of time needed for females of Diaphorina citri to start oviposition on new shoots of citrus under screen-house conditions (bars with different letter differ statistically by Tukey-HSD test, P < 0.05).
Table 1.
Mean values (± SEM) of eggs, nymphs and total viability of Diaphorina citri on flush shoot stages of 'Valencia' sweet orange plants grafted on 'Swingle' citrumelo under controlled environmental room (CER) and screen-house (SH) condition.
Fig 6.
Schedule of Diaphorina citri emergence.
Total number of adults emerged per day (circles) and synchrony proportion (%) of female (squares) and males (triangles) of Diaphorina citri in experiment performed under screen-house conditions (*, ** indicate adjusted residuals greater than │1.65│ for P-value < 0.10) and│1.96│ for P < 0.05, respectively).