Reported volume percentile diameter at a pressure of 310 kPa, \* Droplets have been categorized based on DV0.5 as per ASABE S-572.3 standard [29].

## *3.2. Canopy Deposition*

There were no significant differences in deposition for the main effects of SSCDS treatments (*F1,108 = 0.49, p = 0.48*), canopy zones (*F2,72 = 0.23, p = 0.79*) nor leaf surface (*F1,108 = 1.14, p = 0.29*) (Table 4) from ANOVA. Likewise, no significant interaction effects were detected. Although not significant, the modified irrigation micro-emitter treatment provided numerically higher overall spray deposition (955.5 ± 153.9 ng cm<sup>−</sup>2) (mean ± standard error of mean [SEM]) compared to the hollow cone nozzle SSCDS (746.2 ± 104.7 ng cm<sup>−</sup>2) (Figure 6).


**Table 4.** ANOVA of cube root transformed canopy deposition data.

#### 3.2.1. Canopy Zone Level Deposition

ANOVA indicates non-significant differences in spray deposition among the canopy zones for both SSCDS treatments (Table 4). Moreover, there was no significant interaction effect between treatments and canopy zones. The bottom zone deposition for modified irrigation micro-emitter treatment i.e., T1 (1630.5 ± 401.1 ng cm<sup>−</sup>2) was the highest followed by the bottom zone deposition for hollow cone nozzle treatment i.e., T2 (1022.3 ± 209.2 ng cm<sup>−</sup>2) (Figure 6a). The least spray deposition was reported for the top canopy zone in treatment T1 (493.1 ± 117.6 ng cm<sup>−</sup>2) and was significantly different than bottom zone deposition of corresponding treatment. These results indicate that similar deposition in different canopy zones may be achieved with modified irrigation micro-emitter SSCDS.

#### 3.2.2. Leaf Surface Level Deposition

Spray deposition data collected at samplers installed on abaxial and adaxial surface of the leaves revealed that there was no significant difference in spray deposition on either surface of leaves regardless of the SSCDS treatments. Moreover, there was no significant interaction between treatment and leaf surface (Table 4). The highest spray deposition was reported for adaxial leaf surface treated with modified irrigation microemitter i.e., T1 (1112.3 ± 242.2 ng cm<sup>−</sup>2) followed by hollow cone nozzle SSCDS i.e., T2 (914.5 ± 167.1 ng cm<sup>−</sup>2) (Figure 6b). The abaxial deposition in T1 (798.7 ± 190.1 ng cm<sup>−</sup>2) was also numerically higher than T2 (577.9 ± 123.4 ng cm<sup>−</sup>2). Nevertheless, the differences were not significant with an HSD test. Furthermore, the CV in spray deposition on the leaf surfaces for T1 and T2 were 23.2% and 31.9%, respectively.

**Figure 6.** Mean spray deposition evaluated at (**a**) different canopy zones and (**b**) leaf surfaces for modified irrigation micro-emitter (T1) and hollow cone nozzle (T2) treatment. Different lowercase letters above individual bar plots indicate significance of mean differences in transformed data at 5% level and associated error bars indicate standard error; nontransformed deposition (ng cm<sup>−</sup>2) values are presented.

## *3.3. Canopy Coverage*

**Table 5.** ANOVA result of cube root

There was no significant difference in coverage corresponding to the SSCDS treatment (*F1,108 = 1.2, p = 0.27*) and canopy zones (*F2,72 = 0.36, p = 0.70*) (Table 5) as main effects. On the contrary, a significant coverage difference was reported between the leaf surfaces (*F1,108 = 8.91, p = 0.02*). Furthermore, there was no significant interaction between SSCDS treatments, canopy zones, and leaf surfaces. Overall, modified irrigation micro-emitter had numerically higher canopy coverage (22.7 ± 2.6%) compared to hollow cone nozzle SSCDS (19.0 ± 2.8%).

> canopy coverage data.


transformed


#### 3.3.1. Canopy Zone Level Coverage

There was no significant difference in spray coverage among canopy zones regardless of the SSCDS treatments (Table 5). Moreover, no significant interaction was reported between canopy zone and SSCDS treatment. The bottom zone coverage of modified irrigation micro-emitter treatment i.e., T1 (34.6 ± 5.3%) was highest followed by bottom zone coverage of hollow cone nozzle treatment i.e., T2 (26.0 ± 5.7%) (Figure 7a). Moreover, top zone coverage of T1 (15.5 ± 3.9%) was significantly lower than bottom zone coverage. The least canopy coverage was reported for mid zone canopy coverage of treatment T2

(15.3 ± 3.9%). Furthermore, unlike T1, the differences in bottom and top zone coverage (15.8 ± 4.0%) for T2 were statistically non-significant.

**Figure 7.** Mean spray coverage assessed at different (**a**) canopy zones and (**b**) leaf surfaces for modified irrigation microemitter (T1) and hollow cone nozzle (T2) treatments. The lowercase letters above individual bar plots indicate the significance of mean differences in transformed mean at 5% level and associated error bars indicate standard error; non-transformed coverage (%) values are presented.

#### 3.3.2. Leaf Surface Level Coverage

There was a significant difference in abaxial and adaxial sample coverage for both SSCDS treatments (Figure 7b). However, interaction effect between treatment and surface was not significant (Table 5). The adaxial leaf surfaces of the canopies treated with modified irrigation micro-emitter (T1) received the highest spray coverage (31.7 ± 3.9%) followed by the adaxial leaf surfaces (28.2 ± 4.3%) of hollow cone nozzle SSCDS (T2) treated canopies. Moreover, abaxial coverage for T1 (13.7 ± 3.0%) and T2 (9.9 ± 3.2%) was significantly lower than corresponding adaxial coverage. Further analysis indicates that the CV in spray coverage among the leaf surfaces for T1 and T2 were 55.9% and 68.1%, respectively.

#### *3.4. Off-Target Drift Losses*

#### 3.4.1. Ground Run-Off and Drift Losses

There was no significant difference in deposition for sub-tree run-off obtained from modified irrigation micro-emitter i.e., T1 (1720.6 ± 289.3 ng cm<sup>−</sup>2) and hollow cone nozzle treatment i.e., T2 (1785.3 ± 435.6 ng cm<sup>−</sup>2) (Table 6). Moreover, the percent of applied active ingredient lost underneath the tree for T1 (45.3%) was marginally lower than T2 (47.4%). The analysis of coverage samplers exhibited similar results. The treatment T1 and T2 had a coverage of 36.9 ± 5.7% and 35.3 ± 7.6%, respectively.

Mid-row ground drift deposition data collected at 1.5, 4.5 and 7.5 m downwind indicate that mean ground deposition for modified irrigation micro-emitter treatment, i.e., T1 (121.8 ± 43.4 ng cm<sup>−</sup>2), was numerically lower than hollow cone nozzle SSCDS, i.e., T2 (447.4 ± 190.9 ng cm<sup>−</sup>2) (Table 7). However, the difference among them were nonsignificant. Additionally, the percent of applied active ingredient lost to the ground drift for T1 (3.2 %) was considerably lower than T2 (20.8%). Furthermore, T1 had significantly lower mid-row ground deposition (364.4 ± 85.3 ng cm<sup>−</sup>2) at 1.5 m downwind distance compared to T2 (1306.9 ± 465.3 ng cm<sup>−</sup>2) (Figure 8a). The measured mid-row ground deposition at 4.5 and 7.5 m downwind for treatment T1 was also lower than T2; however, the difference was not significant. Similar trends were observed for the analysis of coverage samplers. The mean coverage corresponding to T1 (4.8 ± 1.7%) was lower than T2 (20.5 ± 6.2%); however, the difference was not significant (Table 7). Likewise, the coverage observed at

1.5 m downwind distance for treatment T1 (14.3 ± 3.3%) was significantly lower than T2 (61.0 ± 8.0%) (Figure 8b).

**Table 6.** Mean sub-tree run-off evaluated for tested treatments.


\* Transformed data were used for statistical analysis; presented data are non-transformed values in (mean ± SEM) format; different lowercase and uppercase letters represent the differences (significant or not significant) in transformed mean at α = 0.05; # The values in the square bracket represents the percent of applied active ingredient lost underneath the tree.

**Table 7.** Mean mid-row ground drift losses evaluated for tested treatments.


\* Transformed data was used for statistical analysis; presented data are non-transformed values in (mean ± SEM) format; different lowercase and uppercase letters represent the differences (significant or not significant) in transformed mean at α = 0.05; # The values in the square bracket represents the percent of applied active ingredient drifted on the ground. The lowercase and uppercase letters in superscript indicates the significant differences in transformed mean at α = 0.05.

**Figure 8.** Mean mid-row ground (**a**) deposition and (**b**) coverage assessed at 1.5 m, 4.5 m and 7.5 m downwind for tested SSCDS treatments (i.e., T1 and T2). The lowercase letters above the line markers indicate the significant differences in transformed mean at α = 0.05 and associated error bars indicate standard error; presented values are non-transformed mid-row ground deposition (ng cm<sup>−</sup>2) and coverage (%).

#### 3.4.2. Aerial Drift Losses

Mean aerial deposition for modified irrigation micro-emitter i.e., T1 (0.7 ± 0.1 ng cm<sup>−</sup>2) was significantly lower than hollow cone nozzle SSCDS treatment, i.e., T2 (3.2 ± 0.4 ng cm<sup>−</sup>2) (Table 8). Additionally, the percent of applied active ingredient lost to the aerial drift was negligible for both treatments (0.02, and 0.08% for T1 and T2, respectively). Similar aerial deposition trends were observed at 3 and 6 m downwind (Figure 9a). Additionally, the deposition evaluated at various sampling heights (i.e., 3.3, 3.6, and 3.9 m above ground level) for treatment T1 (1.0 ± 0.5, 0.6 ± 0.3, 0.4 ± 0.2 ng cm<sup>−</sup>2, respectively) was significantly lower than T2 (3.9 ± 1.0, 2.8 ± 0.9, 2.9 ± 0.9 ng cm<sup>−</sup>2, respectively) (Figure 9b). However, the sampling height did not significantly affect the aerial deposition for a particular SSCDS treatment. Analysis of coverage samplers indicated that there was negligible mean aerial coverage (<0.1%) for both the treatments.

**Table 8.** Mean aerial drift losses evaluated for tested treatments.


\* Transformed data was used for statistical analysis; presented data are non-transformed values in (mean ± SEM) format; different lowercase and uppercase letters represent the differences (significant or not significant) in transformed mean at α = 0.05; # The values in the square bracket represent the percent of applied active ingredient drifted into the air; The lowercase and uppercase letters in superscript indicates the significant differences in transformed mean at α = 0.05.

**Figure 9.** Mean aerial deposition observed at (**a**) 3 m and 6 m downwind and (**b**) 3.3 m, 3.6 m and 3.9 m above ground level for tested SSCDS treatments (i.e., T1 and T2). Different lowercase letters above individual bar plots indicate the differences (significant or not significant) in transformed mean at α = 0.05 and associated error bars indicate standard error; presented values are non-transformed mean ground deposition (ng cm<sup>−</sup>2).
