Defendant’s Appeal
[1] Defendant’s sole contention is that the court “erred in permitting the introduction of expert economic testimony on the issue of impaired future earning capacity, as plaintiffs evidence failed to establish a foundation for the recovery of such damages.” Plaintiff offered the testimony of Dr. J. Carl Poindexter, an economics professor at North Carolina State University, to provide expert evidence on plaintiffs damages from his inability to farm tobacco since the accident. Citing Gillikin v. Burbage, 263 N.C. 317, 139 S.E. 2d 753 (1965) and its progeny, defendant contends Dr. Poindexter’s testimony was inadmissible absent independent expert medical testimony establishing the cause of plaintiffs disability. We disagree.
Defendant’s argument overlooks the well-established principle in North Carolina that, in many instances, lay testimony is competent to establish the cause of an injured plaintiffs disability. McGee v. Insurance Co., 51 N.C. App. 72, 275 S.E. 2d 212, disc. rev. denied, 303 N.C. 181, 280 S.E. 2d 452 (1981); Goble v. Helms, 64 N.C. App. 439, 307 S.E. 2d 807 (1983), disc. rev. denied, 310 N.C. 625, 315 S.E. 2d 690 (1984); Brandis, N.C. Evidence, Sec. 129 (2d rev. ed. 1982). The recent North Carolina Rules of Evidence do not change this rule. See N.C. Gen. Stat. § 8C-1, Rule 701. Plaintiff testified that, prior to the accident, he farmed at least twelve hours per day without getting tired, but that, after the accident, his diminished capacity to farm owing to fatigue has forced him to farm less and to give up farming his tobacco crop. We hold that this testimony, standing alone, is sufficient to establish causation. McGee, supra. Plaintiff here actually more than satisfied his burden of showing causation by presenting, in addition to his own testimony, the testimony of family members and a number of friends and expert medical testimony linking his injuries from the accident to his disability.
Having presented sufficient evidence of causation, plaintiff thus was entitled to introduce expert evidence on his damages from this disability. See N.C. Gen. Stat. § 8C-1, Rule 104(b). Accordingly, we hold that the Court did not err in admitting the testimony of Dr. Poindexter.
*458 Plaintiff’s Cross-Assignment of Error
[2] Pursuant to N.C.R. App. Proc. 10(d), plaintiff attempts to cross-assign as error the court’s award of interest from the date of the jury’s verdict. Plaintiff maintains that (1) to the extent defendant had liability insurance covering plaintiffs claims, the court should have awarded interest on the judgment from the date the action was instituted instead of from the date the jury reached a verdict and (2) for that portion of the judgment not covered by liability insurance, the court should have awarded interest from 31 May 1984, the date a directed verdict was entered in the first trial against plaintiffs negligence claim. Plaintiffs cross-assignment of error constitutes an attack on the judgment and not an alternative basis in law for supporting the judgment. Ordinarily, this type of conditional appeal is not allowed. Rule 10(d) of the North Carolina Rules of Appellate Procedure; Stevenson v. Dept. of Insurance, 45 N.C. App. 53, 262 S.E. 2d 378 (1980). However, by order of this Court dated 4 May 1987 we allowed plaintiffs motion pursuant to Rule 2 for review of his cross-assignment of error by writ of certiorari under Rule 21(a).
The applicable statute governing prejudgment interest in the instant case is former N.C. Gen. Stat. § 24-5 (1983 Cum. Supp.) prior to its amendment in 1985. See 1985 N.C. Session Laws, ch. 214. Former G.S. § 24-5 provides, in pertinent part, that:
The portion of all money judgments designated by the fact-finder as compensatory damages in actions other than contract shall bear interest from the time the action is instituted until the judgment is paid and satisfied, and the judgment and decree of the court shall be rendered accordingly. The preceding sentence shall apply only to claims covered by liability insurance. The portion of all money judgments designated by the fact-finder as compensatory damages in actions other than contract which are not covered by liability insurance shall bear interest from the time of the verdict until the judgment is paid and satisfied, and the judgment and decree of the court shall be rendered accordingly.
Based on this statute, plaintiff now argues for the first time on appeal that the trial court should have awarded prejudgment interest from the date his action was instituted, to the extent that defendant had liability insurance covering plaintiffs claim. *459However, plaintiff did not address the question of liability insurance at trial. He neither presented any evidence nor made any request for findings on this issue. Accordingly, we hold that, because plaintiff failed to raise this issue at trial, he is now precluded from raising it for the first time on appeal.
We further hold, however, that, notwithstanding plaintiffs failure to raise the question of liability insurance, the court should have awarded interest from 31 May 1984, the date a directed verdict was entered in the first trial against plaintiffs negligence claim. See Jackson v. Gastonia, 247 N.C. 88, 100 S.E. 2d 241 (1957). Accordingly, we vacate that portion of the judgment ordering plaintiff to recover interest on the judgment from 9 June 1986, the date of the jury’s verdict in the second trial, and remand the cause for entry of a judgment ordering plaintiff to recover $600,000 with interest from 31 May 1984, the date a directed verdict was entered in the first trial against plaintiff s negligence claim.
No error in part, vacated in part, and remanded.
Judges ARNOLD and ORR concur.